How can I stop unwanted group FaceTime calls?

Coming out of work, I received a spam group text about an “outstanding traffic ticket” I supposedly have (I don’t have a license yet). I left it be to delete once I got in the car. I got rid of it and later on in the day, I get a notification to join a FaceTime call with the same spam group that texted me. I’ve tried everything I could and read: silence unknown callers, remove number or cloud ID, etc. I even dared to answer the call only to immediately hang up to block all 20 numbers, and yet it’s still there on my FaceTime app as an active call to join. I have no clue what to do. Does anybody have an answer to help me out?

[Re-Titled by Moderator]

Original Title: Started with a spam group text, now I have a FaceTime call that won’t go away from them